Engineering Commons^™

Stress Analysis Of A Wall Footing Subjected To External Vertical Loads And Overturning Moments By The Finite Element Method, Adil Godiwalla

Masters Theses

"This investigation pertains to the stress analysis by the finite element method of a wall footing subjected to external vertical loads and external overturning moments. This problem has been reduced to a two-dimensional stress analysis problem by taking a unit length of the wall. A rectangular plate - element is used throughout this investigation. The development of the matrix equations is shown and the solution is performed by digital computer. Stresses in the horizontal direction show essentially linear variation which is in agreement with simple structural theory, while stresses in the vertical direction show severe perturbation near the column load. …

Digital Filter Design And Evaluation, David Alvarado MaguiñA

Masters Theses

"This thesis is concerned with the application of two digital filter design techniques to the Pade approximate continuous filters. The (m, n) Pade approximant has a numerator polynomial of degree n in s and a denominator of degree n in s. The (n-1, n) approximates are desirable for linear phase low pass filters, pulse delay circuits without initial condition errors, and pulse forming networks. A collection of plots is shown to demonstrate the quality of the approximations in the frequency domain, as far as amplitude and phase are concerned. These low pass approximants are normalized to a cut-off frequency of …

A Multiple-Input Chemical 'Memistor' For Adaptive Circuits, Richard Franklin Crall

Masters Theses

"A modification of Widrow’s "memistor" is made in a form suitable for extension to multiple-input devices. This modified form is extensively investigated using analog field maps, and through experimental testing. The multiple-input device presented exhibits good adaptive characteristics and reduces the number of interconnections required in the external circuitry"--Abstract, page ii.

The Recovery And Characterization Of Organic Micropollutants From Missouri Subsurface Waters, John Warren Smith

Masters Theses

"The main objectives of this investigation were the recovery and partial characterization of organic micropollutants from Missouri subsurface waters and the evaluation of the number of filters in series required for effective removal of organic materials from water using the Carbon Adsorption Method.

The organics were recovered from a spring and two deep wells using three large capacity (1. 5 cu. ft.) activated carbon filters in series. Chloroform and ethanol were employed as primary elutants, but acetone and benzene were also investigated. Characterization was by organoleptic, chemical, and biological determinations, toxicity measurements, and solubility partitioning.

Organic materials were found in …

Dynamic Response Of A Simply Supported Beam To An Accelerating Point Load, Joseph Victor Cusumano

Masters Theses

"An analysis based on linear theory is presented for determining the dynamic response of a simply supported beam on an elastic foundation acted upon by a moving time dependent point force with axial forces included. This thesis extends the present theory to include an analysis of a point force accelerating uniformly across the beam. In particular, it is shown that the customary resonance conditions which are prevalent for a point force moving with uniform velocity no longer exist for the case of a point force accelerating uniformly across the beam.

The basic problem and its solution are presented for a …

The Measurement Of Explosively Induced Stresses In Rock-Like Materials With A Capacitive Transducer, Vincent Paul Crane

Masters Theses

"A capacitive transducer was developed for measuring the free surface motion in Hydrostone blocks loaded by an explosive plane wave generator approximately one foot from the specimen. The charge to specimen distance was adjusted to produce a single spall, the position of the fracture being noted on the recovered specimen. The longitudinal wave velocity in each specimen was determined by the ultrasonic pulse technique before each shot. From the above measurements the stress, strain and strain rate at the point of fracture were determined. An attempt was made to determine the actual fracture time with imbedded [sic] conductive graphite rods, …

Quality Of Surface And Subsurface Water In A Missouri Carbonate Karst Terrain (Dry Fork, Norman, And Benton Creek Watersheds), James Chi Huang

Masters Theses

"Little is known about the effect of carbonate karst terrain on water quality in the United States. Karst topography occurs over a large portion of Missouri and over a significant part of other midwestern states. The objectives of this study were the determination of the quality of surface and subsurface water in carbonate karst terrain and the investigation and evaluation of the effect of rainfall and runoff on water quality in the Meramec Spring area, east of Rolla, Missouri, during both the dry and wet seasons over the period of one year. Water samples were collected at a large number …

Small-Signal Impedance Of A Junction Diode At High Injection Levels, John E. Lundy

Masters Theses

"A mathematical expression for the driving point impedance of a junction diode at high injection levels is developed. To evaluate the impedance versus frequency characteristic of a diode, it is necessary to know the minority carrier lifetime as a function of injection level and doping density in the base (lightly doped) region, the junction area, and the base width. The interesting characteristic of the diode impedance at high injection levels is the inductive reactance displayed by the diode.

The expression is developed by solving the differential equation for charge flow in the base region of a diode assuming space-charge neutrality …

Film Boiling From Horizontal Plates With Low Thermal Capacity, K. M. Ragsdell

Masters Theses

"The object of this investigation was to obtain data for saturated film pool boiling from a low thermal capacity flat plate at atmospheric pressure. A test plate, constructed from resistance strip, was placed horizontally in a pool of liquid, and was heated electrically. Refrigerant-11 and nitrogen were used as the boiling liquids. Heat transfer results were obtained in both fluids over a temperature range of approximately 1200F⁰ (400-1600⁰F). Surface size, roughness and orientation effects were observed for flat horizontal heated surfaces with one dimension near the most dangerous wavelength. No surface material effect was observed. Excellent correlation of the data …

A Study Of Film Boiling Of Liquid Nitrogen And Liquid Argon Over A Wide Pressure Range With Cylindrical Heaters, V. J. Flanigan

Masters Theses

""A film boiling heat transfer study was conducted with three different diameter cylindrical copper heaters over a wide range of pressures for nitrogen and argon with the heat transfer surface in the horizontal position. The data were compared to the commonly used film boiling heat transfer relations. The common relations were found to be considerably in error for the range of variables covered in this investigation. A semi-empirical equation for corresponding states fluids which correlates the available data as a function of the reduced temperature and reduced pressure was derived and discussed"--Abstract, page iii.

Construction Of A Laboratory Type, Convertible Excitation Argon Laser, Arthur P. Reckinger

Masters Theses

"The purpose of this thesis is to describe the construction of a general purpose, convertable [sic] excitation, laboratory type, argon laser. Quartz tubing was used in the final model while attempts to use alumina were made during earlier work. The final model has total optical power output of 230 mw at a discharge current of 29 amperes in the dc excitation mode. Provision was also made to utilize RF or pulsed excitation. The device is built so that several values of optical transmittance are available with a wide range of mirror placement"--Abstract, page ii.

A Transmission Electron Microscopy Study Of Some High Strength Plain Carbon Steels, George Joseph Vytanovych

Masters Theses

"Methods of preparing foils of high strength, heat treated, plain carbon steels for examination in the electron microscope by the transmission technique were perfected and are described. Two processes for the initial thinning of a bulk sample were successful. A chemical process was found to be more rapid but not satisfactory for small samples. A mechanical process was slower, but was applicable to the smaller specimens. Electro-polishing the thinned material yielded acceptable foils from which photomicrographs of good quality were obtained. The microstructure of the high strength steel samples showed typical tempered martensite. No reasons for the differences in ductility …

The Transient Dynamics Of Plane Mechanisms, Navnit Chhaganlal Mehta

Doctoral Dissertations

"Accurate determination of dynamic characteristics of mechanisms has become more important with increased requirements on speed, efficiency and precision. Many devices, such as circuit breakers and computing mechanisms, operate under purely transient conditions and actuation time places a serious limitation on the response of the system of which these devices are a part.

In the classical analysis, whether it be graphical or analytical, the mechanism is assigned a specified position and state of motion from which the forces required to produce the motion can be determined. The inverse problem of specifying the driving force and determining the resulting motion, which …

A Structural Investigation Of Bismuth Ferrate And The Bifeo₃-Pbzro₃-Pbtio₃ Ternary System, Gary D. Achenbach

Doctoral Dissertations

"Solid state reaction of Bi₂O₃ · Fe₂O₃ mixtures was shown to yield impure bismuth ferrate, BiFeO₃, containing Bi₂Fe₄O₉ and residual Bi₂O₃; this places the results of much of the literature based on BiFeO₃ prepared by this technique in suspect. Single phase polycrystalline BiFeO₃ was prepared by multiple nitric acid leaching of sintered samples which contained excess Bi₂O₃ to prevent the formation of Bi₂Fe₄O₉ during sintering. X-ray and neutron powder diffraction data indicate that …

An Investigation Of The Creep Characteristics Of Portland Cement Mortar Under Static And Dynamic Strain, Ikram-Ul-Haq Dar

Doctoral Dissertations

"The combined effect of static and dynamic loads on design of underground openings is currently receiving much attention. It is known that the time-dependent behavior of rock is considerably different when a dynamic load is superimposed on prestressed rock. The shape of an underground opening has a definite influence on the magnitude of the local stresses and these may be significantly larger than those due to the weight of the overlying rock alone. Under these conditions, even a small dynamic load in the form of vibrations caused by blasting, drilling and related operations may increase the stress beyond a critical …

Centrifugal Model Study And Finite Element Analysis Of Stress Near A Fault, Christopher Haycocks

Doctoral Dissertations

"The adverse effects of faults on the stability of underground openings has long been realized. To date, however, discontinuities and most other types of geologic heterogeneities have not been amenable to mathematical analysis using the classical theories of elasticity and plasticity. This investigation examines the stress distribution around a single discontinuity and compares the experimental and numerical methods used for the analysis. The theory of elasticity, employing the equations of compatibility, equilibrium etc., was used to determine a stress function for the stress distribution around a circular hole loaded in a centrifugal field. The analysis was terminated after the stress …

Matrix Computer Analysis Of Curvilinear Grid Systems, David Leon Fenton

Doctoral Dissertations

"A general equilibrium-stiffness method of matrix structural analysis was adapted and applied to the solution of the member end forces and moments of each of the members in a curvilinear structural grid system. A structural system of this nature is commonly used as the supporting framework for a "steel-framed dome", in addition to being a basic structural component in many aerospace applications. An integral part of the development of the analysis was the development of a computer program to perform the many complex operations required to obtain the solution. The engineer, by supplying the appropriate structural data and load data …

The Amino Acid And Monosaccharide Content Of The Cell Walls Of Thiobacillus Thiooxidans, Edward Hibbert Crum

Doctoral Dissertations

"The objectives of this investigation were: (a) to culture large quantities of Thiobacillus thiooxidans cells, (b) to find an acceptable method of rupturing the cells, (c) to find an acceptable method of isolating the cell walls, and (d) to analyze the cell wall components, especially the amino acid and sugar components. The strain of T. thiooxidans used for this investigation was American Type Culture Collection Number 8085. The surface active agents Tergitol 08 and Tween 80 were investigated for their ability to reduce the lag period found in the growth of T. thiooxidans. Although a concentration of 12.5 ppm Tween …

Numerical Approximation To Performance Predictions Of Gas-Drive Reservoir With Or Without Gas-Cap And Gas Injection, Jagannath Rao Ghole

Doctoral Dissertations

"The pressure-saturation transient history for a hydrocarbon reservoir is solved for solution-gas, gas-cap and injected-gas drives assuming the saturation-pressure variations depicted by Muskat, under specific restrictive assumptions. A prototype reservoir system and its transient pressure saturation distribution under production is systemized on an IBM 360-Model 40 Computer which allows the definition of the transient behavior of saturation with pressure declination and fluid withdrawal for preassigned initial saturations of the oil, water and gas phases. This analysis is then modified for the existence of a gas-cap and for the re-injection of produced gas volumes for pressure maintenance considerations and the ensuing …

A Study Of Surface And Geometric Effects On The Nucleate Boiling Of Liquid Nitrogen And Liquid Argon From Atmospheric To The Critical Pressure, Calvin Benson Cobb

Doctoral Dissertations

"A maximum heat flux correlation was derived for corresponding states liquids and subsequently verified by the data collected in this study as well as data presented in the literature. By applying this correlation, one can predict maximum heat flux values at high pressures from maximum heat flux values measured at low pressures; however, to apply the correlation it is necessary to have at least one maximum heat flux value and the saturation temperature at which it was determined.

Contrary to existing correlations, it is shown that for any nucleate boiling heat transfer correlation to be truly general, it must include …

Stresses In A Thick Spherical Shell, David Wayne Moore

Masters Theses

"This thesis reports a method to evaluate the stresses in a segment of a thick spherical shell. In the numerical examples loads due to thermal expansion as the shell is constrained at the free edge and a dead load acting vertically downward were considered for a shell assumed pinned but free to rotate and for a shell assumed completely fixed at the edge. A concrete shell was specifically studied but the method would also apply to a shell of any homogeneous, isotropic material"--Abstract, page i.

The Realization And Application Of Parallel Linear Feedback Shift Registers, Ross K. Heitzmann

Masters Theses

"Two methods for serial-to-parallel transformation of linear feedback shift registers are briefly discussed. A third method for transformation is rigorously developed using a next-state and output equation representation of the linear feedback shift register. An algorithm is developed for simplifying the parallel machine resulting from serial-to-parallel transformation, where simplification is defined as reduction in the required number of modulo 2 adders. A computer program incorporating serial-to-parallel transformation and the simplification algorithm is provided "--Abstract, page ii.

Convective Heat Transfer In Small Cylindrical Enclosures Heated From Below, Donald Wayne Land

Masters Theses

"Free convection in enclosed air spaces is often of prime importance in the design and analysis of panels utilizing the insulating properties of air and other gases. Previous investigations were performed on very thin air layers.

This thesis presents the results of an experimental investigation to determine the heat transfer by convection and conduction through air layers with relative sizes in terms of length/diameter ratios of one-fourth to one.

Eight cylindrical samples were tested. Four had inside diameters of 2.0 inches, and the others were 2.75 inches in diameter. Heat was transferred across the air layers by both conduction and …

Some Aspects Of Transient Flow Behavior In Artesian Aquifers And In Hydrocarbon Reservoirs Surrounded By Artesian Aquifers, Alton John Nute

Masters Theses

"An analysis of the principal theories concerning the transient movement of water in artesian aquifers and from artesian aquifers into hydrocarbon reservoirs is presented. Various analytical methods which can be applied to depict the behavior of these two types of aquifer systems are compared.

Most aquifer studies to date have been based upon the Thesis Non-Equilibrium Formula. This equation has been used to calculate the coefficients of storage and transmissibility for aquifers; to evaluate well performance; and to investigate problems concerning recharge, movement, and discharge of aquifer water. However, one problem which still remains is that of accurately predicting the …

Characteristic Impedance Of Open Microstrip Transmission Lines Having Finite Thickness And Multiple Dielectric, Philip Julian Carter

Masters Theses

"A computer program is provided for determining the characteristic impedance of microstrip transmission lines having finite thickness. Infinite and finite ground planes are incorporated into the program. The programmer need only supply information in the form of a data card. This procedure is clearly outlined.

Graphical solutions of characteristic impedance for multiple dielectric microstrip transmission line problems are obtained using a discrete resistive analogue. Computer network analysis programs are viewed as having several advantages not possessed by the physical resistive analogue"--Abstract, page 2.

Collision And Pursuit Course Terminal Closures For Spacecraft To Satellite Rendezvous, John Anthony Campbell

Masters Theses

"Collision and pursuit course closure maneuvers were studied for correcting position and velocity errors in the terminal phase of spacecraft to satellite rendezvous.

Minimum values of the ratio of initial range to velocity necessary to achieve rendezvous were determined for collision closures as a function of the initial line of sight. The time and velocity increment required for rendezvous were computed as a function of initial conditions.

Pursuit closure maneuvers were analyzed and time and velocity increments defined as a function of initial range, closing velocity, line of sight angle and angular velocity.

The velocity increments required were significantly higher …

A Comparison Of Friction And Drum Hoisting Systems On An Energy-Input Basis, Hemendra Nath Kalia

Masters Theses

"The purpose of this thesis is to provide a suitable basis for comparing the relative advantages of the friction and drum hoists under various conditions of operation.

Such comparisons are mainly and necessarily based upon physical characteristics of the mechanisms for lack of appropriate economic data. It is believed, however, that this inadequacy may be alleviated to some extent by substituting comparative theoretical energy requirements of' the two hoisting systems under identical duty conditions over a practical range of mining situations involving various depths and daily productions.

This has been accomplished by adapting a computer to standard mine-hoist design techniques …

A Comparison Of Strength Properties Of Heat Treated Aisi 1065 Steels At High Strength Levels, Robert Lowell Hollenbeck

Masters Theses

"Six AISI C 1065 steels were heat treated and tensile tested in order to evaluate their ductility at high strength levels. Heat treating and tensile testing procedures were developed for use working with these steels at tensile strengths of 300,000 psi and higher. The austenitizing procedure in the hardening operation was found to affect the strength and ductility of the high strength samples. Rapidly heating to the austenitizing temperature followed by an immediate quench produced better properties than slow heating followed by a soaking period before the quench. However, it was concluded that the carbon contents of the steels studied …

A New Performance Index For Sensitivity And Energy Optimization., Mohamed Zafer Dajani

Masters Theses

"The principal aim of this thesis is to present a new index of performance which when minimized will simultaneously optimize the system energy and sensitivity function of a multivariable linear control system. With this performance index it is usually desirable to discriminate between the sensitivity factor and the energy term by weighting them differently. Two types of weighting factors are presented. Since it is not easy to minimize that performance index for all types of problems, further research is suggested to find methods of solution for such problems. Illustrative examples demonstrate the optimization process and the type of assumptions needed …

A Study Of The Compressibility Of Silty Soils., Marvin L. Byington

Masters Theses

"This study has been conducted to determine the applicability of the Terzaghi Theory of Consolidation and to determine the compressibility of silt soils with varying clay content. A pure silt was extracted from the Lebanon Silt Loam and mixed with varying amounts of the Onyx Cave Illite-Chlorite Clay. The compressibility of these mixtures was determined and an attempt made to apply the Terzaghi Theory in the analysis. It was found that the compressibility of soils high in silt content is very low. It was also found that the Terzaghi Theory may be applied to mixtures of 15 percent or more …